Fisher plow P/T fuse blows - sometimes ??

[Gordon Gould]

Not a tractor problem but a 3 cable Fisher plow with isolation module in my truck. There is a 15 amp inline fuse from the battery to the iso module labled P/T (Park/Turn) fuse. This fuse blows a couple time a season and I lose the directionals and parking lights on the plow but the truck lights all still work. When I replace it every thing works fine. I have inspected the cable harnesses and connector/socket wiring and they all look good. I can't get into the iso module itself. Does any one have any suggestions on where else to look. I do run my emergency flashers w/ the lights on a lot but it seems a 15 amp fuse should run the four 1157 bulbs on the plow with both filaments on. (I am guessing that is what it does) . Thanks for any thoughts.

gg

 

[RNeumann]

Typically something like that is the bulb sockets. Coat the socket and bulb base is petroleum jelly and make sure the lens baskets are good

 

[Rustyiron]

Gordon didn't you have an old fisher under hood belt drive pump?
Check out one of the snowplowing forums, they have "sections" for each brand's electrical gremlin questions. Snowplow Forums

 

[RNeumann]

The connector between the plow and vehicle could also use some petroleum jelly

 

[Gordon Gould]

Typically something like that is the bulb sockets. Coat the socket and bulb base is petroleum jelly and make sure the lens baskets are good

Thanks RN. I do use dielectric grease on the cable connectors and bulb bases. I am not sure what you mean by lens baskets. These are the four 1157 type bulbs in the head gear and everything seems solid.

gg

 

[Gordon Gould]

Gordon didn't you have an old fisher under hood belt drive pump?
Check out one of the snowplowing forums, they have "sections" for each brand's electrical gremlin questions. Snowplow Forums

Thanks for that link Eric - Electrical Gremlin sounds like the right place to look !

This is just a straight 9' Minute-Mount 2 plow on my 2001 Ram 3500. That under the hood system was one that I took off an old Ford for a guy who wanted to restore the truck. I used the blade and A-frame on my tractor plow and ended up giving the pump and valve away as I couldn't fine any one who wanted to buy them.

gg

 

[Gordon Gould]

Typically something like that is the bulb sockets. Coat the socket and bulb base is petroleum jelly and make sure the lens baskets are good

Blew the fuse again. This time when I carefully inspected the wiring again I actually took apart the lamp sockets. When I pushed one of the wires that went in the back of the socket out thru the front of the socket I found the problem. The wire was crimped onto the little bulb contact bead. Half the strands were in the crimp and half the strands were sticking out at a right angle with burnt ends. The thing went for several years before it started giving problems.

gg

 

[RNeumann]

Blew the fuse again. This time when I carefully inspected the wiring again I actually took apart the lamp sockets. When I pushed one of the wires that went in the back of the socket out thru the front of the socket I found the problem. The wire was crimped onto the little bulb contact bead. Half the strands were in the crimp and half the strands were sticking out at a right angle with burnt ends. The thing went for several years before it started giving problems.

gg

Even a broken clock is right twice a day. I guess sometimes I get lucky!

Anyway, glad you found it. Some of those little gremlins are frustrating

 

[Gordon Gould]

Even a broken clock is right twice a day. I guess sometimes I get lucky!

Anyway, glad you found it. Some of those little gremlins are frustrating

I just thought you would find that amusing - I am the lucky one I figure.

gg